Percutaneous access to the kidney (PAK) or renal access is a minimally invasive procedure for establishing a keyhole access in percutaneous nephrolithotomy (PCNL) to remove a kidney stone. In this procedure, a trocar is passed through a patient's skin through the body layers into the kidney to reach a stone target. Surgical instruments such as guidewire, ultrasonic probes and vacuum are then passed through the hole in the trocar to carry out the stone removal process.
Conventionally, a PAK procedure is carried out by a surgeon holding a trocar in his hand with one end of the trocar resting on a patient's skin. The other end of the trocar is tilted numerous times to establish an accurate alignment between the trocar and the stone target. The alignment of the trocar is determined with the help of a C-arm fluoroscope. Once the accurate alignment is confirmed, the surgeon has to maintain the alignment of the trocar by steadying his hand. The trocar is subsequently pushed into the patient's body to reach the stone target.
The duration of the trocar insertion procedure typically ranges from 10 minutes to 1.5 hours and throughout the procedure, the C-arm fluoroscope has to be in operation. Consequently, both the patient and surgical crew are subjected to long exposure of X-ray and this could be a potential health hazard in the long run. In addition, due to the elaborate procedure, there may be instances when the trocar has to be withdrawn and the entire procedure needs to be repeated. This may aggravate the condition of the patient as multiple punctures of the kidney may increase the risks to the patient such as significant bleeding, haematoma formation and infection. The procedure may have to be called off and rescheduled, thus causing much distress to the patient and loss of precious time of the healthcare professionals.
To address the problems above, robotic arms are used to perform the trocar insertion procedure. For example, current approaches utilise robotic arm surgical systems which mimic the standard manual percutaneous renal access. In other words, the systems are manually controlled by the surgeon, e.g. using a manipulator such as a joystick, to align the trocar with the kidney stone. Also, these conventional systems are bulky and slow in processing. It is also expensive to manufacture the systems and implement the trocar insertion procedure using the systems.
A need therefore exists to provide a system for aligning a surgical tool that seeks to address at least some of the above problems.